Cell Membrane

[fran008]

'The cell membrane is an effective barrier between the cell and the surrounding environment' this is quoted from my teacher's biology notes...but how applicable it is? What makes it sooo effective?

[sdekivit]

it can regulate what goes in and out for most compounds through membrane channels and transporters (except for certain drugs / steroids / fats and water)

[Navin]

Being partially(selectively) permeable, the cell surface membrane "selects" what enters or leaves the cell.

[new_guy]

for example , the ammount of sodium/natrium ion inside the cell must always be smaller than outside of the cell (sorry for the bad biology language ..) , cell membrane will make sure that these condition will not change , it does need ATP
I think...... please correct me if I'm wrong ...

[Morris]

Yes it needs ATP, because Na is more concentrated out the cell than in; to maintain concentration cell must expel ions agains theri gradient and this proces needs ATP.

[Poison]

Yes, active transport needs ATP but passive transport doesn't.

[rambo]

'The cell membrane is an effective barrier between the cell and the surrounding environment' this is quoted from my teacher's biology notes...but how applicable it is? What makes it sooo effective?

too add on to the cell membranes list of its use, it is made up of proteins and fats therefore its helps the cell stay durable for its time of use.

[rambo]

for example , the ammount of sodium/natrium ion inside the cell must always be smaller than outside of the cell (sorry for the bad biology language ..) , cell membrane will make sure that these condition will not change , it does need ATP
I think...... please correct me if I'm wrong ...

WOW U SOUND CONFUSED. BUT ITS COO CUZ ITS SIMPLE. U MUST BE TALKING ABOUT THE SODIUM PUMPS IN OUR CELL MEMBRANES. ON OUR CELL MEMBRANES WE HAVE THIS TUBES THAT ARE CIRCULAR CALLED GLOBULAR PROTEINS THOSE ARE THE ACTUAL GATES FOR SODIUM AND POTASSIUM EXCHANGE. FOR EVERY 3 SODIUMS INSIDE THE CELL IS EXCHANGED FOR 2 POTASSIUM IN EXTRACELLULAR FLUID. THEN VICE VERSA. ATP IS NEEDED TO ACTIVATE THE OPENING OF THE GLOBULAR PROTEIN (WHICH IS LOCATED ON OUR MEMBRANE). FATS HOLD THESE PROTEINS TOGETHER FORMING THE CELL MEMBRANE.

[baikuza]

he..he..
says
1. semi-permeable property
2. hydrophobic properties
3. regulation (vacuola contractile)(mm.. Energies are needed)
4. the lipid bilayer structure (hei.. thanks poison )
5. a place for the "sensory part"(u know just like at limfosit T and ..hei there are so much to mentioned here)-this make cell take response(s) on thing(s) out side there.
6. mm.. a place where metabolic processes take place (hei there are ATP,GTP,CTP,TTP...UTP(?))
7. .....(lost of word)

[Terry K.]

Also, the cell membrane is important in the Na+/K+ pump. This uses Na+ to generate a gradient by which i believe ATP can be formed. Also, it is important in the membrane certain organelles in order to create a proton pump which I know is used to generate ATP.

[new_guy]

There are so many things I don't know about Biology.......(Man.. I'm REALLY POOR at Biology)...
Will I be good at Biology

There will be the answer.... Let It Be...

[Terry K.]

Believe you me, Biology is probably the most complicated science in the world, only because everything changes and adapts to its environment, and we have to find out why. It takes nerve and will, but beyond that, Biology is probably also the most interesting and fun science in the world. For me, it's between chemistry and biology, but that's only because I want to go into the field of Forensic Analyzing(If you watch CSI, you know "Greg", the lab guy, that's what I want to do, because he's the one that actually solves the crimes) DON'T WORRY, Biology comes with time, just give it a good effort and it should all come to you easily after that!!!